Material Return Phenomenon In Jaw Crusher

In the working process of jaw crusher, sometimes raw materials will be squeezed out from the feed opening, which is also called material return phenomenon. In other words, while working, raw materials are pushed out from the feed opening by the jaw plates instead of being crushed. Then how does this happen and how to solve this problem? In this article, we introduce reasons about material return phenomenon in jaw crusher and its solutions.

Reasons About Material Return Phenomenon

The Unbalanced Force On The Raw Material

The raw materials to be crushed in the crushing cavity stay balanced without moving up and down. But when the angle between fixed jaw plate and movable jaw plate increases, the vertical force on the raw materials lose its balance and the force upward in stronger than the force down. In this case, the raw materials will be pushed by the upward force to the feed opening, which will cause to the material return.

The Discharge Opening Is Too Wide

For crushers with same specifications, if the discharge openings are different, the angles between movable jaw plate and fixed jaw plate are also different. The wider the discharge opening, the bigger the angle will be.

Friction Factor Between Material And Jaw Plates

In jaw crusher, manufacturers generally adopt tooth board in jaw plates is to increase the friction factor between raw materials and jaw plates. If the friction factor is too big, it will be very difficult to crush the raw materials and also cause badly damage to the jaw plates, which might lead to material return.

Besides, the actual size of spare parts do not match with the drawings, the great difference between raw materials sizes will also might lead to material return phenomenon.

Solutions About Material Return

Manufacturers should strictly follow the drawings while processing spare parts and make sure the spare parts reach to standard. Also, manufacturers should recommend suitable jaw crusher according to the requirements of customers. For operators, when the jaw plates or other parts wear badly, deal with them timely. If the sizes of raw materials differ greatly, the operator should screen them first and put the raw materials nearly the same size together. This will also effectively reduce the raw material return phenomenon.